NUCLEATION,POLYMERIZATION, AND PRECIPITATION OF FeOOH1

Fresh Fe(ClO₄)₃ solutions, 0.01 M or 0.001 M in iron (III), were seeded with iron (III) hydroxide brown sols and the reaction processes were investigated. In two experiments, HC1O₄ was added to fresh Fe(ClO₄)₃ solutions to lower their degrees of super saturation with respect to iron (III) hydroxide. Depending upon the quantity of seeding solution added, it was found that samples differed greatly in appearance and in the stability during ageing. With a small amount of seeding solution added and following a relatively long induction period, the sample rapidly developed to a dense, cloudy yellow suspension with FeOOH precipitate settled shortly afterwards. With an increased amount of seeding solution added, the sample gradually became more brownish and less turbid and eventually a clear brown sol was observed. Although α-FeOOH was the major hydrolysed species in all samples, a yellow precipitate which settled under gravity was found only in those containing a small quantity of seeding solution. The above results provide experimental evidence supporting the hypothesis (Hsu and Ragone, 1972) that the initial number of nuclei relative to the concentration of mono-meric species is the key factor governing the appearance and the stability of an hydrolysed iron (III) solution. In another experiment, varying amounts of a seeding solution were added to a fresh, pure 0.001 M Fe(ClO₄)₃ solution to which no HC1O₄ was added. All samples rapidly hydrolysed to clear brown sols in less than 6 hours and no noticeable seeding effect was observed. It is suggested that a pure 0.001 M Fe(ClO₄)₃ solution is highly supersaturated with respect to iron (III) hydroxide and a large number of nuclei spontaneously form in situ shortly after preparation.     

Effects of various mating stimuli on pituitary release of luteinizing hormone in the gilt

Twenty-four nulliparous crossbred gilts approximately 9 months of age were assigned to either a naturally mated (NM), artificially inseminated (Al) or non-mated control group (C). All gilts were fitted with indwelling cephalic cannulas for collection of blood samples for subsequent hormonal analyses every 10 min for the first 24 hr of the periestrous period. Plasma luteinizing hormone (LH) concentrations were not affected by type of mating. The mean duration of the LH surge for Al group was less than the C or NM groups (44.5 vs 67 and 87 hr (P<.05)). Mean maximal LH concentrations for the Al and NM groups occurred prior to the control group (P> 05). Area under the LH release curve and number of episodic surges were not different for the three treatments. Length of standing estrus and exposure time to back pressure were not different among treatment groups.The results suggest that stimulation of the pelvic region during either natural mating or artificial insemination did not enhance release of LH. Mated gilts did exhibit different secretory patterns of LH release than non-mated gilts.     

80 years of the Society of Friends of the University of Veterinary Medicine Hannover

The Society of Friends of the University of Veterinary Medicine Hannover was established in 1926, in times of severe economical distress. According to its statutes its main purpose from the beginning was to complement the governmental budget of the University. During its 80 years of existence the so called "Friendly Society" has contributed to overcome many financial shortages in research, clinics and institutes. In addition it supported veterinary students in need. Some aspects of the Society's history and activities will be communicated.     

Musculoskeletal disorders and psychosocial risk factors among veterinarians in Queensland, Australia

Objective   Although musculoskeletal disorders (MSD) represent one of the most important occupational health issues in contemporary society, few studies have specifically investigated this problem among veterinarians.
Design   An anonymous questionnaire survey mailed to all veterinarians registered with the Veterinary Surgeons Board of Queensland during 2006.
Results   Almost two-thirds of respondents (63%) had experienced MSD of the lower back, 57% had experienced neck-related MSD, 52% had experienced shoulder-related MSD and 34% had experienced MSD of the upper back during the previous 12 months. MSD was statistically correlated with a range of psychosocial factors, including stress associated with career structure, time pressures, client's attitude, lack of recognition by the public, lack of recognition by colleagues, lack of understanding from family or partners and work stress because of insufficient holidays each year.
Conclusion   Overall, this study has demonstrated significant correlations between MSD and psychosocial risk factors among a large cohort of veterinarians, apparently for the first time in the published literature. The results also suggest that personal and workplace issues may contribute more to the development of MSD among veterinarians than many of the previously recognised ergonomic risk factors.     

Distinct habitat selection by freshwater morays in tropical rainforest streams

Morays occupy unique interstitial habitats and function as key predators in marine ecosystems. Conversely, there is limited understanding of the ecology of Gymnothorax polyuranodon, the lone representative of the family Muraenidae known to reside in freshwater systems. In this study, we used field‐based encounters over a 3‐year period in three short–steep–coastal–streams of the Australian Wet Tropics to find that most G. polyuranodon individuals (74%) occupied pools, with very few individuals observed in run (23%) or riffle (3%) mesohabitats. Moreover, G. polyuranodon positively selected microhabitats of slow flow (<0.05 ms^?1) and deep water (>80 cm), while avoiding high flows (>0.5 ms^?1) and shallow water (<40 cm depth). Morays exhibited strong preferences for boulders (73% of the immediate stream bed area occupied relative to 36% availability) with most individuals resting directly underneath large or very large boulders. Collecting and compiling records of this rare and elusive species over the long‐term helped to reveal such habitat specialisation. Future management plans for G. polyuranodon should focus on preserving boulder interstices year‐round and maintaining stream‐sea connectivity to facilitate a diadromous life cycle.     

Evaluation of intraperitoneal and intrahepatic administration of a euthanasia agent in animal shelter cats

One hundred eighty-one adult cats, with body weight greater than 1.8 kg, were obtained from animal shelters, then were administered a sodium pentobarbital-lidocaine euthanasia agent by either the intraperitoneal (IP; n = 77) or intrahepatic (IH; n = 85) route. A preliminary study (n = 19 cats) indicated that most cats gave no indication of perception of injection (responding) if restraint was minimal and injection was rapid. During IP injection, 3 of the 77 cats (4%) responded (turned the head backward or vocalized). Of the 85 cats given IH injection, 8 (9%) responded; however, no response approached the magnitude of that observed after IM injection of ketamine hydrochloride. After either injection route, cats were observed for excitement (any exaggerated activities of stage-I and -II anesthesia (eg, vocalizing, flopping, sneezing, licking, running, paddling), and after cardiac standstill, cats were necropsied to identify exact location (final site) of the injection. Of 53 initial IP injections, final site for 22 (42%) was in the peritoneal cavity (PC). Use of a sideport needle (n = 24) did not significantly increase accuracy of IP injection. The small and large intestines were penetrated by 27% (15/55) of the IP injections from the right side, and the spleen was penetrated by 32% (7/22) of the left-side injections. Intrahepatic injection was significantly (P less than 0.05) more accurate, with 70 of 85 (82%) of the final sites being the liver only, the liver/PC, or the PC only. Twenty-five percent (13/53) of IP injections resulted in excitement (all stage-I and -II anesthesia-exaggerated activities cumulative to 30 seconds).(ABSTRACT TRUNCATED AT 250 WORDS)     

Chondrodysplasia in Australian Dexter cattle

Objective To describe the occurrence of chondrodysplasia in Australian Dexter cattle.
Design A pathological and genetic case report.
Procedure Congenital lethal chondrodysplasia was studied in two female Dexter foetuses aborted mid to late gestation. Clinicopathological findings including histological changes in limb bones, and analysis of pedigree information were evaluated.
Results Characteristic features of congenital lethal chon-drodysplasia (Dexter bulldog) include abortion, disproportionate dwarfism, a short vertebral column, marked micromelia, a relatively large head with retruded muzzle, cleft palate and protruding tongue and a large abdominal hernia. Histological changes in limb bones are consistent with failure of endochondral ossification. Dexter chondrodysplasia is considered to be inherited in an incompletely dominant manner with the homozygous form producing the congenital lethal condition. A preliminary minimum estimate of heterozy-gote frequency is 19% within the registered Australian Dexter herd, based on analysis of the contribution of three obligate heterozygotes whose semen has been widely used by artificial insemination in Australia.
Conclusion Dexter chondrodysplasia is present in Australian cattle and further cases of the homozygous form, congenital lethal chondrodysplasia, are likely to occur.
Recommendation It is requested that spleen and liver tissue from bulldog foetuses and blood from their parents be collected to assist research into Dexter chondrodysplasia.